Electrical instrument type relay



Oct. 25, 1960 med Bag. 15. 1958 J. FASSAK, JR., ETAL LECTRICAL INSTRUMENT TYPE RELAY 3 Shee ts-Sheet 1 JOHN FASSAK JR.

WILL/AM A. R0)

INVENTORS Oct. 25, 1960 J. FASSAK, JR., EIAL 2,957,956

ELECTRICAL INSTRUMENT TYPE RELAY 3 Sheets-Sheet 2 Filed Dec. 15, 1958 JOHN FASSAK JR. WILL/AMA R0) INVENTORS W da w TORNE Y Oct. 25, 1960 J. FASSAK, JR., ETAL ELECTRICAL INSTRUMENT TYPE RELAY s Sheets-Sheet 3 Filed Dec. 15, 1958 JOHN FASSAK JR. WILL/AH A ROY INVENTORS TOR/YE) United States Patent ELECTRICAL INSTRUMENT TYPE RELAY John Fassak, Jr., East Paterson, and William A. Roy,

Clark, N.J., assignors to Daystrom, Incorporated, Murray Hill, N.J., a corporation of New Jersey Filed Dec. 15, 1958, Ser. No. 780,538

6 Claims. (Cl. 20056) This invention relates to an electrical relay and more particularly to an electrical relay of the instrument type which includes one or more adjustable contacts.

Relays of the type contemplated by this invention include a movable coil rotatable in a flux gap in a suitable magnetic structure. A zero-adjuster mechanism comprising a rotatable shaft extending through a hole formed in the cover of the instrument provides means whereby the normal, or zero current, position of the movable coil may be altered by rotation of the shaft. A pair of movable contacts are suitably secured to the movable coil, and rotate therewith. The movable contacts cooperate with adjustable contacts mounted on suitable adjustable index arms, or pointers, which arms are individually adjustable from the front of the instrument by suitable adjusting knobs, or the like. In prior art arrangements, at least three holes are provided in the front of the cover, one for each adjusting knob, and one for the Zero connector arrangement. In the relay of our invention, the rotatable shaft of the zero-adjuster mechanism, and the adjusting knobs for adjustment of the adjustable relay contacts are coaxially arranged and extend through a single hole in the face of the instrument.

An object of this invention is the provision of an instrument type relay having a pair of adjustable contacts which contacts are mounted on arms which are adjustably positioned by means of coaxially positioned adjusting knobs extending from the said instrument.

An object of this invention is the provision of an instrument type relay having a zero adjuster shaft extending through the cover of the instrument, and contact adjusting knobs coaxially mounted with the said zero adjuster shaft, which knobs set the high and low opening and closing positions of the relay.

An object of this invention is the provision of a unitary stop, or abutment, construction for limiting the respective high and low settings of first and second adjustable index arms, or pointers, in an instrument type relay.

An object of this invention is the provision of an instrument type relay of pleasing appearance which includes a single hole in the face of the cover through which the zero corrector shaft and movable contact adjustment knobs coaxially extend.

An object of this invention is the provision of an economically manufactured and assembled movable contact, and zero corrector, adjustment means for instrument type relays.

These and other objects and advantages will become apparent from the following description when taken with the accompanying drawings. It will be understood that the drawings are for purposes of illustration and are not to be construed as defining the scope or limits of the invention, reference being had for the latter purpose to the appended claims.

In the drawings wherein like reference characters denote like parts in the several views:

"ice

embodying our invention, parts being shown broken away for clarity;

Figure 2 is an enlarged fragmentary top view of the instrument with parts shown broken away for clarity;

Figure 3 is an enlarged fragmentary first view of the instrument with the cover removed therefrom;

Figure 4 is a view which is similar to Figure 3 only showing the scale plate and bracket assembly with the crank arms and zero adjuster shaft supported thereby removed from the instrument;

Figure 5 is a View which is similar to Figure 4 only showing the bracket assembly secured to the instrument; and

Figure 6 is a View which is similar to Figure 5 only showing the one crank arm mounted thereon.

Reference is first made to Figure 1 of the drawings wherein a housing for the relay is shown comprising a generally cylindrical-shaped base 10 with a transparent cover 11 removably secured thereto by any suitable means not shown in the drawings. The electrical instrument mechanism, which may be of any desired type, is shown Figure l is a side elevational view of an instrument comprising a cylindrical yoke 12 of soft iron material within the cylindrical bore of which is suitably mounted a permanent core magnet 13 (as seen also in Figure 4). The instrument mechanism is secured to the bottom of the instrument base by any suitable means not shown. As best seen in Figure 2, top and bottom bridges 16, 16 are secured together, and to the soft iron yoke 12. Conventional jewel bearing assemblies, including jewel bearings 17 (only the front jewel bearing being shown in the drawings) are coaxially supported by the bridges 16, 16. The front jewel bearing assembly is mounted Within a hollow hub 18 suitably attached to the front bridge. Conventional threaded means (not shown in the drawings) are located within the hub 18 and provides means for axially positioning the jewel bearing 17. A movable coil 19 is provided with pivots 21 at opposite ends thereof (only the top pivot being shown in the drawings) which pivots are rotatably supported in the jewel bearings 17. A pointer 22 is fastened to the pivot 21 and is bent, substantially, as shown in Figure 1, whereby the upper free end thereof is movable in front of a scale plate 23. As seen in Figure 2, the scale plate 23, together with a bracket 24 of non-magnetic material, are secured to the top bridge 16 by screws 26, 26 engaging threaded holes in the said bridge. The scale plate 23, as shown in Figure 3, may be provided with suitable scale markings 23.

As seen in Figures 1 and 2, first and second movable relay contact arms 27 and 27 are insulatingiy supported on the pivot base 21 and are thereby rotatably movable upon rotation of the coil 19. Suitable electrical connecting means, not shown in the dra ings, connect the movable contact arms to electrical terminals at the rear of the base, two such terminals 3e, 3% being shown in Figure 1. An abutment 29 is attached to the pivot base 21, and is secured to the inner end of a conventional spiral spring 31. The outer end of the spiral spring is secured to an abutment 32 which abutment is rotatably mounted on the hub 18 extending from the bridge 16. It will be understood that a similar spiral spring arrangement is provided at the bottom of the instrument mechanism, not shown in the drawings. Eiectrical current may be conducted to the coil 19 through the spiral springs and abutments, as is well known.

The rotatable outer abutment 32, as best seen in Figures 1 and 4, is provided with a downward extension 34 having an elongated slot 34 (see Figure 4) formed therein; the said extension comprising a Zero-adjuster arm for the instrument. As seen in Figure l, a rotatable zero corrector shaft 37 having a crank pin 33 extending from the end thereof is rotatably mounted in a bushing 39 secured to the bracket 24. The pin 38 engages the elongated slot 36 in the zero-adjuster arm 34 whereby rotation of the Zero corrector shaft 37 produces pivotal movement of the zero adjuster arm 34. Thus, it will be understood that thenormal, orzero current, position of the movable coil 19, can be altered by rotation of the zero corrector shaft 37. Rotatable adjusting knobs 43 and 44- for positioning of adjustable relay "contacts of the instrument are coaxially mounted with the said zero corrector shaft. The coaxial arrangementv of adjusting knobs and zero corrector shaft, described in detail hereinbelow, comprises one important aspect of our invention.

A stop member 46 of insulating material is mounted on the hub 18 extending from the top bridge 16, adjacent the movable abutment 32. The stop member is provided with a forwardly extending integral flange 46' upon which adjustablecontactcarrying relay index arms, or pointers, 4S and 49 are rotatably mounted. The arms 48 and 49 are separated on the hub by an insulating washer 51 and electrical connection to the arms is made by metallic washers which abut the same. The washers are provided with radially extending tabs 52 and 53, shown in Figure 4, which are electrically connected to terminals at the rear of the case by means not shown in the drawings. A locking nut 54 having an inwardly extending axial'fiange portion, as seen in Figure 1, threadedly engages the free threaded end of the hub 18 to secure the adjustable abutment 32, stop member 46, index arms 48 and 49 and the associated electrical contact making washers and insulating washers to the hub.

Contact arms 56 and 57 are integrally formed on the index, or pointer, arms 48 and 49 and extend inwardly thereof. The contact arms 56 and 57 are adapted to cooperate with the respective movable contacts 27 and 27' secured to the pivot base 21. Thus, it will be understood that when the coil 19 with the attached movable contacts pivots a sufficient amount in one direction, electrical connection is made between contacts 27 and 56 and, likewise, when the coil pivots sufficiently far in the other direction, electrical connection is made between contacts 27 and 57. The index arms 48 and 49 are adjustably positioned whereby both the low value of coil current at which the relay contacts 27 and 56 close, and the high value of coil current at which the relay contacts 27 and 57 close, are adjustable. In prior art arrangements individual index arm adjusting knobs extend through separate holes formed in a cover 11, which knobs engage the individual index arms for rotatable adjustment thereof. In our novel arrangement, the adjusting knobs 43 and 44, for adjustably positioning the respective index arms 48 and 49 extend coaxially with the zero connector shaft 37 through a single hole in the cover.

As best seen in Figures 1 and 6, the inner knob 43 is provided with an integrally formed crank arm 61 having an inwardly extending crank pin 62 integrally formed adjacent the free end thereof. The pin engages an elongated slot 63 formed in an enlarged section of the index arm 48. As best seen in Figures 2 and 3, a similar crank arm 61 is formed on the outer knob 44, which crank arm includes a crank pin 62' which, in turn, engages an elongated slot 63 formed in an enlarged section of the index arm 49. Thus, it will be understood that the index arms 48 and 49 (which carry the adjustable relay contacts 56 and 57) are adjustably positioned by rotation of the coaxial knobs 43 and 44, respectively.

Relative rotation of the crank arm 61 in a clockwise direction, as viewed in Figure 3, and the arm 61 in a counter-clockwise direction is limited by engagement of the pin 62' on the arm 61' with the arm 61. The pin 62 is shown :abutting the arm 61 in .the broken line showing :of the arm 61' in Figure 3. :Possible damage to the relay contacts .by excessive relative movement of r 4 the crank arms and knobs is thereby eliminated by engagement of the pin 62 with the arm 61.

Limits on the counter-clockwise movement of the index arm 48 and clockwise movement of the index arm 49 are provided by the stop member 46 mounted on the hub 18. It will be first noted that rotary movement of the stop member on the hub is prevented by means of rearwardly extending protrusions 66, 66 formed on the stop member which protrusions engage the underside of the front bridge 16, as best seen in Figures 1 and 2. Stop elements 67 and 67' are integrally formed on the stop member 46, which elements are adapted to engage the index arms 48 and 49, respectively. As best seen index arm 49. As seen in Figure 3, grooves 69 and 69' are formed in the face of the stop elements 67 and 67,

respectively, for reception of the connecting tabs 52 and 53. The edge of the index arms engage the stop elements 67 and 67 in the limiting position of the arms. The

. unitary construction of the stop member with the resultant ease in assembly thereof in the instrument comprises another important feature of our invention.

The novel zero corrector mechanism and index arm adjusting means of our invention is simply and inexpensively manufactured and easily assembled. The knobs 43 and 44, bushing 39, zero corrector shaft 37, and stop member 46 are easily molded from suitable plastic material, such as nylon, or the like, while the crank arms 61 and 61' are easily punched from similar material, if not formed integrally with the respective knobs 43 and 44. The knob 43 and crank arm 61 are preferably made of one material with a color, while the knob 44 and crank arm 61 are made of a material which would have a different color. The associated index arms are painted the same color. By color coding the knobs and associated pointer, or index arm, one source of error resulting from turning the wrong knob is removed. The simplicity of assembly of our novel coaxial contact setting and zero corrector arrangement will be apparout upon examination of Figures 4-6. In Figure 4, the index pointers 48 and 49, together with our novel stop member 46, are shown mounted on the top bridge 16 of the instrument. The assembly of the parts illustrated in Figure 4 is substantially the same as that followed in the assembly of many prior art instrument type relays. In Figure 5, the scale plate 23 and bracket 24 are shown secured to the top bridge by the screws 26 which engage tapped holes in the said bridge. The bushing 39 and zero corrector shaft 37 are attached to the bracket 24 and form a sub-assembly therewith. Next, as seen in Figure 6, the inner knob 43 and attached, or integrally formed, crank arm 61 are placed over the bushing 39, with the pin 62 engaging the elongated slot 63 formed in the index arm 48. In like manner, as seen in Figure 3, the outer knob 44 and attached or integrally formed crank arm 61 are placed over the inner knob, with the pin 62 in engagement with the elongated slot 63' found in the index arm 49. The knobs and arms are maintained in operative position upon placing the cover 11 on the instrument. As shown in Figure 1, the inner and outer knobs 43 and 44 extend through a hole 76 formed in the cover, while a flange 77 formed on the outer knob 44 engages the cover adjacent the periphery of the hole 76. No additional fastening means are necessary to secure the knobs and associated crank arms in the instrument.

The zero corrector shaft 37 which terminates within the inner knob 43, is provided with a kerf, or slot, 79 in the outer end thereof for screw driver adjustment of the zero corrector mechanism. Rotation of either'adjustable: knob 43 or 44 will not effect the zero corrector shaft vposition. The coaxial arrangement'of the zero corrector shaft and adjustable knobs is not only easily manufactured and assembled, but also enhances the appearance of the instrument.

Having now described our invention in detail in accordance with the patent statutes, various changes and modifications will suggest themselves to those skilled in this art, and it is intended that such changes and modifications shall fall within the spirit and scope of the invention as recited in the following claims.

We claim:

1. In an instrument type relay comprising a zero corrector shaft and an adjustable relay contact, a rotatable knob operatively connected to the adjustable relay contact for movement thereof, and means forming a bore through the said knob within which bore the said zero corrector shaft extends, the end of the zero corrector shaft being accessible through the open end of the bore in the said rotatable knob for rotatable adjustment of said zero corrector shaft.

2. The invention as recited in claim 1 wherein the relay includes a cover having a hole formed therein through which hole the said rotatable knob extends, means forming a flange on the knob, the said cover abutting the knob flange and limiting movement of the said knob in one axial direction.

3. An instrument type relay including a moving coil connected to a movable zero corrector abutment through a spiral spring, first and second movable relay contacts attached to the moving coil and movable therewith, first and second adjustable relay contacts adapted to cooperate with the respective first and second movable relay contacts, a rotatable zero corrector shaft, means connecting the said rotatable zero corrector shaft to the said movable zero corrector abutment for movement thereof, first and second rotatable knobs coaxially mounted with the said zero corrector shaft, and means connecting the said first and second rotatable knobs to the respective first and second movable relay contacts for movement thereof.

4. In an instrument type relay having a movable coil and first and second movable relay contacts secured to the said movable coil for movement therewith, a hub coaxially mounted with the pivot axis of the said movable coil, a stop member secured to the said hub adjacent the movable coil, first and second index arms rotatably mounted on the hub in axially displaced relation forwardly of the said stop member, means forming a contact on each of the said index arms for cooperation with the respective movable relay contacts, first and second stop elements integrally formed on the said stop member and extending forwardly therefrom, the said first stop element being adapted to engage the said first index arm to limit rotational movement thereof in one direction and the said second stop element being adapted to engage the said second index arm to limit rotational movement thereof in the other direction, and means rotatably adjusting the individual first and second index arms.

5. The invention as recited in claim 4 wherein the said means rotatably adjusting the individual first and second index means includes means forming elongated slots in the said index arms, first and second crank arms coaxially mounted for rotation about an axis parallel to the pivot axis of the said movable coil, first and second crank pins positioned adjacent the free ends of the said crank arms and engaging the respective elongated slots in the said index arms, the said first crank arm abutting the said second crank pin to limit relative rotary movement of the index arms.

6. In an instrument type relay having a movable coil and first and second movable relay contacts secured to the said movable coil for movement therewith, first and second index arms coaxially mounted in axially displaced relation for rotation about the pivot axis of the said movable coil, means forming elongated slots in the said index arms, means forming a contact on each of the said index arms for cooperation with the respective movable relay contacts, first and second crank arms coaxially mounted for rotation about an axis parallel to the pivot axis of the said movable coil, and first and second crank pins positioned adjacent the free ends of the said crank arms and engaging the respective elongated slots in the index arms, the said first crank arm abutting the said second crank pin to limit relative rotary movement of the index arms.

References Cited in the file of this patent UNITED STATES PATENTS 2,537,582 Grace Jan. 9, 1951 2,556,138 Knudsen June 5, 1951 2,824,926 Daschke Feb. 25, 1958 2,851,552 Murphy Sept. 9, 1958 2,895,030 Hotine July 14, 1959 

